The present invention relates to a method and an apparatus for producing a panel of plastic material. The invention was developed in particular for the production of panels having at least a first region formed by at least one plate of thermoplastic or thermosetting material, possibly coated, moulded by thermo-compression and at least one second region constituted by injection moulded thermoplastic material. Panels of this kind are used in particular as inner covering panels for vehicle doors, in which the panel region constituted by the coated plate of thermoplastic material is aesthetically more valuable and is used for the upper part of the panel, whilst the injection moulded part made of thermoplastic material, which is less delicate, extends on the lower part of the panel, more prone to be hit by the feet of the persons stepping into and out of the vehicle.
Currently used solutions for the production of panels of this kind require the use of two independent moulding apparatuses, one for thermo-compression moulding of the coated plates of thermoplastic material and the other for the production by means of injection moulding of the complementary panel region. The two panel parts are mutually joined in a subsequent step by means of mechanical anchoring, ultrasonic welding or other fastening method.
European Patent Application No. 1153725 by the same Applicant describes a method and an apparatus for forming, by injection moulding, a component anchored onto a surface of a plate of thermoplastic material whilst said plate is moulded by thermo-compression between the mutually opposite surfaces of two half-moulds. According to the method and the apparatus described therein, an injection moulding cavity is obtained in one of the half-shells and terminates on the thermo-compression moulding surface of the same half-shell.